HCS08 behaviour at cold temperatures

[ramabh]

hi

I am using MC9s08Dv60 HCS08 Freescale microcontroller.

At cold temperatures(-40 degC ) and at Hot temperatures (85 degC) we are always facing different kind of problems.

Some times even no output at all and even we saw some part of flash its been completely overwritten by something(i.e Flash code corruption) and even reset happens.

Whther this corruption of Flash is because of noise or  something?

What may cause this corruption ?

[JimDon]

Please claify -
No output of what?
Are you programming flash at these temperatures?
If so, what code are you using to program with?
Is Flash always corrupted when you see these problems?

If flash is corrupted, you can expect resets and other problems.

[ramabh]

HI

We are using some part of flash as eeprom so there will be chance of writing in flash even at high temperatures.

When ever there is some error i am not checking entire flash,some times i am seeing some data in Flash which is supposed to be empty.

[JimDon]

Double check that your flash writing code is 100% correct.
Are you disabling interrupts during erasing and writing?
Are you sure that FCLK is set correctly?

Make a test where you never write to flash and see what happens.
I say that, because corrupted flash and bad erase/write routines can show up as all sorts
of random problems. If you never write to flash in your code, and it still happens you might be able to rule that out.

Also carefully read the spec as to how temperature affects flash.

Are you using extended temperature parts?

You are right at the limits for normal temperature parts. If you truly need that range, you are not allowing for ANY margins at all. Not good practice.

What about other components in the design of the board?

[ramabh]

Hi

The problem is not happening every time so that i can just comment Flash routines ,its very rare behaviour.

The flash routines are working properly.